JP2014108695A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network system which can use common hardware and software and can efficiently provide identification information to the ECUs.SOLUTION: A network system includes a master ECU and slave ECUs which are connected with the master ECU so as to communicate therewith, operate based on the communication with the master ECU, and conduct the same function operation. Each slave ECU includes a detection part which detects the state of an input line to which a predetermined signal is input from the exterior; and an identification information obtaining part which obtains ECU identification information on the basis of the detected state of the input line.

Description

  The present invention relates to a network system including a plurality of ECUs.

  A control device such as an ECU and a communication terminal are connected to a network system constructed in an office or vehicle (see Patent Document 1).

  When constructing a network system using a plurality of ECUs of the same function, if other ECUs connected to the system simultaneously perform the same operation to each ECU, one operation command may be sent. When the ECU is operated individually or when the operation timing of each ECU is different, it is necessary to identify the ECU.

Therefore, for example, the ECU is identified by the following method.
The input state of an IC (microcomputer or the like) included in the ECU is changed by pull-up or pull-down using a resistor, and the ECU acquires identification information (ID) based on the state.
-Provide an ID registration function in the ECU, and write the ID from the external device after system construction.
-An ID is set in advance in the source code of software executed on the ECU.

Japanese Patent No. 4791301

  In the method of changing the input state of an IC (microcomputer or the like) included in the ECU, the number of product numbers increases because the types of hardware increase. As a matter of course, the number of replenished products also increases and the man-hours for management increase. In the method of providing an ID registration function in the ECU, hardware and software can be shared, but man-hours for writing from an external device are required when setting the ID. In the method of setting the ID in advance in the software source code, since the software becomes individual, the software product number is generated depending on the number of connections of the same ECU. Further, if the number of ECUs is changed on the way, it is necessary to change each time, and expandability is impaired.

  Against the background of the above problems, an object of the present invention is to provide a network system that can share hardware and software and efficiently assign identification information to an ECU.

Means for Solving the Problems and Effects of the Invention

  A network system for solving the above problems includes a master ECU, and a plurality of slave ECUs that are connected to the master ECU so as to be communicable and operate based on communication with the master ECU and perform the same functional operation. The ECU includes a detection unit that detects a state of an input line to which a predetermined signal is input from the outside, and an identification information acquisition unit that acquires the identification information of the ECU based on the detected state of the input line.

  With the above configuration, there is basically only one type of ECU part number. By automatically identifying the ID, hardware and software can be shared, and the load of ECU part number management can be reduced. Further, it is not necessary to write the ID from the outside. Furthermore, even if the number of ECUs is changed, it is possible to cope with it and maintain expandability.

FIG. 1 is a diagram illustrating a configuration example of a network system according to the present invention (first embodiment). The flowchart explaining the identification information acquisition process (Example 1). The figure which shows the structural example of the network system of this invention (Example 2). The figure which shows the example of the wiring form of an input line (Example 2). FIG. 5 is a diagram illustrating an example of connector pin assignment in FIG. 4 (second embodiment); FIG. 10 is a flowchart for explaining another example of the wiring form of the input lines (Example 2). FIG. 7 is a diagram illustrating an example of connector pin assignment in FIG. 6 (second embodiment); The flowchart explaining the further another example of the wiring form of an input line (Example 2). FIG. 9 is a diagram illustrating an example of connector pin assignment in FIG. 8 (second embodiment); FIG. 9 is a flowchart for explaining identification information acquisition processing (second embodiment).

  The network system of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in the network system 1, a master ECU 10 and a plurality of slave ECUs 20, 30, 40, 50 are connected via a LAN 60 so as to communicate with each other.

  In the configuration of FIG. 1, resistors equal to the total number of master ECUs and slave ECUs are connected in series between the power supply line and the ground, the resistance connected to the power supply line is included in the master ECU, and the remaining resistance is 1 Each included in the slave ECU, one end on the power supply line side of the resistance included in the slave ECU is connected to the input line of the slave ECU, the detection unit detects the voltage of the input line, the identification information acquisition unit, This corresponds to obtaining identification information based on the voltage value detected by the detection unit.

  The master ECU 10 includes a well-known CPU 11, a memory 11 a using a nonvolatile storage medium such as a flash memory, a connector 12, a communication interface (hereinafter abbreviated as “communication I / F”) 13, a resistor R 1, and an A / D converter. Including peripheral circuits (not shown). The master ECU 10 acquires the state of the slave ECU (generally referred to as 20, 30, 40, 50 when the symbol is not added, and the same applies hereinafter) through communication, or gives a predetermined operation instruction to the slave ECU.

  In addition, one end (side closer to the power supply line) of the resistor R <b> 1 is connected to the input line 14 of the master ECU 10, and is connected to the power supply line 15 via the connector 12. The other end (the side close to the ground) is connected to the wiring 25 via the connector 12. The wiring 25 is connected to the input line 24 via the connector 22 of the slave slave ECU 20.

  Each slave ECU controls the same functional operation, and controls, for example, a vehicle door lock device, a power window device, and an electric seat device. Therefore, the hardware and software are the same. The slave ECU performs drive control of an actuator (not shown) connected to each slave ECU based on an operation instruction from the master ECU 10, and transmits the state of the slave ECU or the actuator to the master ECU 10.

  Since all the slave ECUs have the same configuration, the slave ECU 20 will be described as an example. The slave ECU 20 is a well-known CPU 21 (detection unit of the present invention, identification information acquisition unit), a memory 21a using a nonvolatile storage medium such as a flash memory, a connector 22, and a communication I / F 23 that exchanges communication signals with the master ECU 10. , Resistor R2, peripheral circuit and actuator drive circuit (not shown).

  A wiring 25 connected to the other end of the resistor R1 of the master ECU 10 is connected to the input line 24 of the slave ECU 20 via the connector 22. One end (the side close to the power supply line) of the resistor R2 is connected to the input line 24. The other end (side close to ground) is connected to the wiring 35 via the connector 22. The wiring 35 is connected to the input line 34 via the connector 32 of the slave slave ECU 30. Therefore, the voltage V2 input to the CPU 21 from the input line 24 is obtained by subtracting the voltage drop of the resistor R1 from Vb.

  The values of the resistors R1 to R5 are preferably the same (R). This configuration corresponds to a resistance value that is the same in all ECUs. With this configuration, it is easy to obtain identification information. The other end of the resistor (R5) of the lowest-order slave ECU (50) is grounded by the wiring (56) via the connector (52).

  As described above, in the configuration of FIG. 1, resistors (R1 to R5) equal to the total number of the master ECU 10 and the slave ECU are connected in series between the power supply line (Vb) and the ground (GND). The one with the highest potential (Vb) at one end on the power line side is input to the master ECU 10, and the potential at one end on the power line side of each resistor is sequentially input to the slave ECU. Therefore, the voltage input terminal of the CPU of the slave ECU is applied by subtracting the sum of the voltage drop due to the resistance of the ECU connected to the upper side (high potential side) from the power supply voltage Vb.

When resistors R1 to R5 have the same value and n master ECUs and slave ECUs are connected in total, the voltage drop Vr per ECU is Vr = Vb / n [V]. Therefore, the voltage Vm of the input line measured by the mth ECU is Vm = Vb− (m−1) * Vr = Vb− (m−1) * (Vb / n) [V].
m = n * (1−Vm / Vb) +1 (Equation 1).
Further, when a wiring (indicated by a broken line) is added to the other end of the resistors R1 to R5 to measure the voltage across each resistor, when a total of n master ECUs and slave ECUs are connected, The voltage drop Vr per ECU is Vr = Vb / n * R. Therefore, the voltage Vm of the input line measured by the mth ECU is Vm = Vb− (m−1) * (Vb / n * R).
m = 2 * Vb / (Vb + R * V) (Formula 2).

  The identification information acquisition process of the slave ECU in the configuration of FIG. 1 will be described with reference to FIG. This process may be executed when the slave ECU is turned on, or may be executed when any communication is received from the master ECU 10. First, the voltage applied to the input line (24 etc.) is measured (S11). Next, identification information is acquired based on the measured voltage (S12). In other words, m is calculated using the above (Formula 1), and this m is used as identification information. Then, the identification information is stored in the memory (S13). Thereafter, this m is read from the memory and used as the identification information of the slave ECU.

  Hereinafter, another example of the network system of the present invention will be described with reference to FIG. 3 and the subsequent configurations have a plurality of input lines, and the identification information acquisition unit corresponds to a unit that acquires identification information based on which input line the detection unit detects a signal.

  Since the configuration of the master ECU 10 is the same as that in FIG. 1, a detailed description thereof is omitted here. Further, since the slave ECU is obtained by removing the resistor (R1 and the like) and the input line (14 and the like) from the configuration of FIG. 1, a detailed description of the CPU, the communication I / F, the memory, and the like is here. Omit. Hereinafter, the slave ECU 20 will be described as an example.

  The connector 22 of the slave ECU 20 is assigned with a power line 26 to which power (Vb) is supplied, a ground line 27 connected to the ground (GND) of the master ECU 10, and a pin to which a communication line 28 connected to the LAN 60 is connected. It has been.

  The acquisition of identification information using the power supply line 26 (a voltage having a predetermined value is applied) will be described with reference to FIGS. 4 and 5. FIG. 4 shows a wiring form of input lines between the connector 22 and the CPU 21. FIG. 5 shows an example of connector pin assignment. This configuration corresponds to a case where a voltage having a predetermined value is input as a signal.

  In this example, a maximum of four power lines 26 can be connected to the slave ECU 20. That is, the power supply line 26 is connected to the pins 222 a to 222 d of the connector 22, and each is connected to the terminals 21 a to 21 d of the CPU 21 via the wirings 26 a to 26 d on the substrate 29. In addition, pull-down resistors (not shown) are connected to the wirings 26a to 26d.

  When a power supply line for supplying power to the slave ECU 20 is separately provided, the connection form of the power supply line 26 to the connector 22 is a form in which the power supply line 26 is not connected to any connector pin (0000) to There are 16 types (1111) in which the power supply line 26 is connected to all the connector pins (represented as connection: 0, non-connection: 1). As a result, 16 slave ECUs can be identified.

  The acquisition of identification information using the power line 26 and the communication line 28 (communication signal) will be described with reference to FIGS. FIG. 6 shows a wiring form of input lines between the connector 22 and the CPU 21. FIG. 7 shows an example of connector pin assignment. In this example, a part of the power supply line 26 and the communication line 28 are not shown, but a maximum of four lines can be connected to the slave ECU 20 respectively.

  The power supply line 26 is connected to pins 222a to 222d of the connector 22, and each is connected to terminals 21a to 21d of the CPU 21 via wirings 26a to 26d. The communication line 28 is connected to pins 221a to 221d of the connector 22, and each is connected to terminals 21e to 21h of the CPU 21 via wirings 28a to 28d. In FIG. 6, the wirings 26c and 26d, the wirings 28c and 28d, and the terminals 21c, 21d, 21g, and 21h of the CPU 21 are omitted. A pull-down resistor (not shown) is connected to the wirings 26a to 26d, and a pull-up resistor (not shown) is connected to the wirings 28a to 28d if necessary.

  In FIG. 6, the communication line actually used for communication with the master ECU 10 is provided separately from the communication line 28 (28a to 28d) described above (connected to the pin 221e) or branched from one of the communication lines 28. Then, it is connected to the communication I / F 23 via the wiring 180 and input to the CPU 21.

  In this configuration, it is possible to identify a maximum of 256 (16 × 16) slave ECUs.

  In the configurations of FIGS. 6 and 7, the identification information may be acquired using only the communication line 28. This configuration corresponds to a communication signal input from the master ECU as a signal.

  The acquisition of identification information using the power supply line 26 and the ground line 27 (ground voltage) will be described with reference to FIGS. FIG. 8 shows a wiring form of input lines between the connector 22 and the CPU 21. FIG. 9 shows an example of connector pin assignment. In this example, the power supply line 26 and the ground line 27 are not illustrated in part, but a maximum of four lines can be connected to the slave ECU 20 respectively.

  The power supply line 26 is connected to pins 222a to 222d of the connector 22, and each is connected to terminals 21a to 21d of the CPU 21 via wirings 26a to 26d. The ground wire 27 is connected to the pins 221a to 221d of the connector 22, and each is connected to the terminals 21e to 21h of the CPU 21 via the wires 27a to 27d. In FIG. 8, the wirings 26c and 26d, the wirings 27c and 27d, and the terminals 21c, 21d, 21g, and 21h of the CPU 21 are omitted. A pull-down resistor (not shown) is connected to the wirings 26a to 26d, and a pull-up resistor (not shown) is connected to the wirings 27a to 27d.

  Even in this configuration, a maximum of 256 slave ECUs can be identified.

  In the configurations of FIGS. 8 and 9, the identification information may be acquired using only the ground wire 27. This configuration corresponds to the input of a ground voltage as a signal. A configuration using the ground line 27 and the communication line 28, or a configuration using all of the power supply line 26, the ground line 27, and the communication line 28 may be used.

  The identification information acquisition process in the slave ECU in the configurations of FIGS. 3 to 9 will be described with reference to FIG. First, the state of the input lines (that is, the terminals 21a to 21d and 21e to 21h of the CPU) is detected (S31).

  When a power supply line or a ground line is connected to the input line, the level of each terminal of the CPU is detected to detect the presence or absence of connection. When the communication line is connected to the input line, it is determined that the communication line is connected when the input level of the terminal changes within a predetermined time.

  Next, identification information is acquired based on the detection state of the input line. For example, referring to the identification information data table stored in the memory, identification information corresponding to the input line detection state is acquired (S32). Then, the acquired identification information is stored in the memory (S33). Thereafter, the identification information of the slave ECU is read from the memory and used.

Next, a communication line for performing communication with the master ECU 10 is determined based on the reception status of the communication signal as described below (S34).
• If a communication line is provided separately from the input line, use that communication line.
If no communication line is provided separately from the input line and there is only one communication line connected to the input terminal of the CPU, that communication line is used.
-When there is no communication line separately from the input line and there are multiple communication lines connected to the CPU input terminal, the communication terminal is detected as the youngest number (or the oldest number) of the input terminal. Use a connected communication line. For example, when communication signals are detected at all of the input terminals, 21a is the youngest number and 21h is the oldest number.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

1 Network system 10 Master ECU
20, 30, 40, 50 Slave ECU
21, 31, 41, 51 CPU (detection unit, identification information acquisition unit)
21a, 31a, 41a, 51a Memory 22, 32, 42, 52 Connector 23, 33, 43, 53 Communication I / F
24, 34, 44, 54 Input line 26, 36, 46, 56 Power line (input line)
27, 37, 47, 57 Grounding wire (input wire)
28, 38, 48, 58 Communication line (input line)
60 LAN
R1, R2, R3, R4, R5 resistance

Claims (7)

A master ECU, and a plurality of slave ECUs that are connected to the master ECU so as to be communicable and operate based on communication with the master ECU and perform the same functional operation;
The slave ECU
A detection unit for detecting a state of an input line to which a predetermined signal is input from the outside;
Based on the detected state of the input line, an identification information acquisition unit that acquires identification information of the ECU;
A network system comprising: Between the power line and the ground, resistors equal to the total number of the master ECU and the slave ECU are connected in series,
The resistance connected to the power line is included in the master ECU, and the remaining resistance is included in the slave ECU one by one,
One end of the resistance included in the slave ECU on the power supply line side is connected to an input line of the slave ECU,
The detection unit detects the voltage of the input line,
The network system according to claim 1, wherein the identification information acquisition unit acquires the identification information based on a voltage value detected by the detection unit.   The network system according to claim 2, wherein the resistance value is the same in all ECUs. There are a plurality of the input lines,
The network system according to claim 1, wherein the identification information acquisition unit acquires the identification information based on which input line the detection unit detects the signal.   The network system according to claim 4, wherein a voltage having a predetermined value is input as the signal.   The network system according to claim 4, wherein a ground voltage is input as the signal.   The network system according to claim 4, wherein a communication signal from the master ECU is input as the signal.

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